Liquid freezing apparatus with renewable freezing wall



Aug. 11, 1964 A. J. ROSS 3,143,865

LIQUID FREEZING APPARATUS WITH RENEWABLE FREEZING WALL Fi-led Dec. 6/1961 2 Sheets-Sheet l #3 4a 4a 43 I 2.

1964 A. J. ROSS 3,143,865

LIQUID FREEZING APPARATUS WITH RENEWABLE FREEZING WALL Filed Dec. 6, 1961 2 Sheets-Sheet 2 2 5 I v I 5 5 n F v v I i v I 5 r 5 I g I 5 I United States Patent 07 3,143,865 LIQUID FREEZING APPARATUS WITH RENEWABLE FREEZING WALL Anthony J. Ross, 116 Myrtle Ave., Elmhurst, Ill.

' Filed Dec. 6, 1961, Ser. No. 157,519

14 Claims. (Cl. 62-354) This invention relates to liquid freezing apparatus and particularly to an apparatus for producing a flake ice product.

The present invention relates generally to liquid freezing apparatus of the type having a rotary ice removing device and an internal evaporator disposed inside the ice removing device. The ice remover is forceably rotated relative to the freezing wall of the evaporator to remove the frozen liquid as it forms on the freezing wall and, in previous constructions of such apparatus, the force which had to be applied to the ice remover to separate the frozen liquid from the freezing wall fluctuated over a relatively wide range during normal operation of the apparatus. It has been found that this variation in force required to separate frozen liquid from the freezing wall is due in a large part to localized cold spots on the freezing wall and that these load variations on the drive motor could be markedly reduced and the overall ice output of the apparatus substantially increased without changing the size of the apparatus or its drive motor, when the freezing wall was cooled substantially uniformly over its entire surface.

An important object of this invention is to provide an ice making apparatus which overcomes the aforementioned problem and provides improved heat transfer from the refrigerant in the evaporator to the liquid to be frozen.

A more particular object of this invention is to provide a liquid freezing apparatus having an improved arrangement for controlling the flow of refrigerant along the freezing wall to eifect substantially uniform cooling of the wall along its length. I

Another object of this invention is to provide a liquid freezing apparatus of the type having an internal evaporator, and which has an improved evaporator construction which facilitates fabrication and assembly of the evaporator and connection of the evaporator to the refrigeration system.

Yet another object of this invention is to provide a liquid freezing apparatus of the type having an internal evaporator and in which the freezing wall of the evaporator is made separate from the refrigerant carrying passages of the evaporator and is afixed thereto in heat conducting relation with the evaporator in such a manner that the freezing wall can be readily removed and installed without opening or otherwise interfering with the closed refrigeration system.

Still another object of this invention is to provide a liquid freezing apparatus having an improved arrangement for mounting and connecting the liquid level control to the water jacket to accurately maintain the proper liquid level in the water jacket.

A further object of this invention is to provide an apparatus for producing flake ice having an improved arrangement for compacting the flake ice and for delivering the compacted ice in discrete blocks. These, together with various ancilliary objects and advantages of this invention will be more readily appreciated as the same becomes better understood by reference to the following detailed description when taken in connection with the accompanying drawings wherein:

FIG. 1 is a side View of the ice making apparatus and with parts of the refrigeration apparatus shown diagrammatically;

FIG. 2 is a longitudinal sectional view through the ice making apparatus;

FIG. 3 is an elevational view of the evaporator insert illustrating the refrigerant flow passages;

FIG. 4 is a transverse sectional view through the ice making apparatus taken on the plane 44 of FIG. 1;

FIG. 5 is a longitudinal sectional view through a modified form of ice making apparatus; and

FIG. 6 is a fragmentary sectional view taken on the plane 6-6 of FIG. 5.

The ice making apparatus of the present invention is intended for use in producing a flake ice product and includes a water jacket 10, and evaporator 11 immersed in the liquid storage chamber C formed by the water jacket, an ice removing device 12 which extends around the evaporator for removing the frozen liquid therefrom, and a drive mechanism 13 for rotating the ice removing device relative to the evaporator. A liquid level control apparatus 14 is provided for controlling the flow of liquid to the liquid storage chamber. The evaporator 11 is connected to a refrigeration apparatus herein shown of the'type having a compressor 16, a condenser 17 and refrigerant supply and return conduits 18 and 19 respectively which connect the evaporator to the outlet of the condenser and the inlet of the compressor. A refrigerant expansion control is provided in the supply line 18 and may include a conventional expansion valve, or a capillary tube such as shown as 18a and 18b in FIG. 2.

As best shown in FIG. 2, the evaporator 11 includes an inner shell 21 which is closed at one end by an end wall 22 and which is open at the other end. The refrigerant supply and return lines extend into the open end of the shell 21 and this end is closed and sealed to the supply and return lines by a plug 23. In the embodiment illustrated, the plug is in the form of an inverted cupshaped member which is pressed into the end of the shell 21 and which is sealed to the shell by solder or by a suit able bonding material such as epoxy type adhesives.

The shell is formed with enlarged portions adjacent each end which defineannular walls 25 and 26 spaced radially outwardly from the shell 21. A tubular sleeve 28 is disposed around the annular walls 25 and 26 and is spaced from the shell 21 to define a refrigerant chamber therebetween. The outer surface of the sleeve 28 forms the freezing wall upon which the ice layer is formed and provision is made for controlling the flow of refrigerant through the chamber 29 between the sleeve and evaporator shell to achieve substantially uniform cooling of the walls along the length thereof. For this purpose, the chamber 29 is divided into at least two flow passagesand provision is made for supplying refrigerant to one of the flow passages adjacent one end of the evapo rator and to the other flow passage adjacent the other end of the evaporator. The flow passages are advantageously of helical configuration and, in the embodiment shown in FIGS. 1-4, the flow passages are in the form of a plurality of grooves designated 31a31d separated by ribs 32. The passages and ribs may be formed as by molding, casting or otherwise attaching helical ribs on the outer surface of the inner shell 21 or by a machining operation in which the helical grooves are cut into the outer surface of the shell. The passages 31a-31d extend in side-by-side helical fashion along the length of the shell 21 and one of the refrigerant supply lines 18a is connected at 35 to one of the grooves 31a adjacent one end of the evaporator, while the other of the supply lines 18b is connected at 36 to a different one of the grooves 31d adjacent the other end of the evaporator. The refrigerant from the inlets 35 and 36 flows in helical fashion through the passages 31a and 31d to the relatively opposite ends of the evaporator. The refrigerant expands as it passes from the inlet along the helical passage to the other end of the evaporator and the cooling effect of the Patented Aug. 11, 1964 a refrigerant changes as more and more of the refrigerant reaches its expanded condition. However, since refrigerant is supplied to relatively opposite ends of the freezing wall and flows in relatively opposite directions therealong, the cooling effect along the freezing wall is substantially uniform. In order to assure substantially com plete expansion of the refrigerant, it is preferable to again pass the refrigerant from the passages 31a and 31d back along the length of the freezing wall. As best shown in FIG. 3, the passage 31a is connected at 37 to the passage 31b at the end of the freezing wall remote from the inlet 35 and the passage 31d is connected to the passage 310 at 38 adjacent the end of the freezing wall remote from the inlet 36. Outlet openings 39 and 40 communicate the remote ends of the passages 31b and 310 respectively with the accumulator chamber 41 and the refrigerant return line 19 extends upwardly into the accumulator chamber and has its open end 42 disposed at a level adjacent at the top of the accumulator chamber to prevent the return of liquefied refrigerant.

As is apparent from FIG. 2, the ribs 32 extend outwardly and engage the outer sleeve 28 to radially support the same. In order to improve the heat transfer between the refrigerant and the surrounding liquid to be frozen, it is preferable to employ a relatively thin outer sleeve or freezing wall 28. The ribs which support the outer sleeve enable the use of a relatively thinner freezing wall than would otherwise be practical and thus contribute to increasing the overall efficiency of the unit. The sleeve is advantageously formed with an inner diameter slightly less than the outer diameter of the ribs and the annular walls 25 and 26 at opposite ends of the shell 21, and the sleeve is applied tothe shell by either heating the outer sleeve or cooling the inner shell sufficient to eifect a temperature difference therebetween adequate to enable axial insertion of the sleeve over the inner shell. When the shell and sleeve are thereafter brought to the same temperature, the shell will be disposed in a tight heat-shrink relation with the sleeve to form a seal between the sleeve and shell and to also firmly radially support the outer sleeve on the walls 25 and 26 and on the ribs 22.

The inner shell 21 is formed with an enlarged head 43 at one end and the outer jacket extends around the head and is sealed thereto as by a gasket 44. The jacket is conveniently formed with a shoulder 45 which is spaced from the end of the jacket a distance to sealingly engage the gasket when the jacket is clamped toa mounting base 46, as by fasteners 47, to seal the interface between the jacket and head. An insulating filler 48 is preferably provided in the underside of the head 43 and in the cup-shaped plug 23 to prevent the accumulation of moisture and ice in this area.

The ice removing device 12 is advantageously in the form of an axially expansible and contractible helical coil having a rounded or blunt ice engaging edge 1211 which engages the ice layer after it has built to a preselected thickness and strips the ice layer off the freezing wall. The separated ice mass is advanced by the helical coil in a direction axially of the liquid hamber C to a discharge opening 51 adjacent the upper end of the chamber. The helical ice removing device has an axially extending shaft portion 52 and an improved arrangement is provided for mounting and rotatably supporting the ice removing device and drive motor 13 to enable ready assembly and disassembly of the parts. As best shown in FIG. 2, the water jacket has an upper end wall 55 conveniently formed integrally with the water jacket and a boss 56 which projects upwardly from the end wall to form a lubricant and dirt collecting reservoir 57. Any excess lubricant which flows into the reservoir can pass outwardly through a drain orifiw 58 formed in the side of the jacket. The shaft 52 on the ice remover extends into a socket 61 formed in a connector member 62 and is non-rotatably connected thereto by a pin 63. The

connector is rotatably supported in the boss 56 by bearings 64 and 65 and the connector is supported against axial movement by a flange 66 at its lower end and by a thrust bearing 67 and split-ring collar 68 at its upper end. The collar is disposed in a peripheral groove in the connector member and releasably retains the connector member in assembled relation on the water jacket. The drive mechanism 13 includes a motor 71 and gear reducer 72, and the gear reducer is detachably secured to the upper end of the jacket as by fasteners 73. The output shaft 74 of the drive mechanism is slidably and non-rotatably connected as by splines 76 to the socket 77 formed in the upper end of the connector 62. In this manner, the axial thrust on the ice removing device is transmitted through the thrust bearing 67 to the water jacket 10, and is not transmitted to the drive mechanism. A grease slinger 79 is conveniently provided on the shaft 74 in overlying relation to the connector 62 to convey the lubricant which may drain from the drive mechanism into the reservoir 57. In the form shown, the motor 71 is disposed at one side of the gear reducer 72 and is preferably counterbalanced by a spring 75.

The liquid level control apparatus 14 regulates the flow of liquid into the chamber 50 to maintain a preselected liquid level therein adjacent the upper end of the evaporator 11. The flow control apparatus includes a reservoir 80, a conduit 81 connected to a source of water under pressure, a valve 82 which regulates the flow of water from the conduit to the reservoir and a float apparatus 83 for operating the valve to maintain a preselected level in the reservoir. In the larger size ice making units wherein the ice is formed at a rapid rate and requires a relatively rapid flow of replenishing water, difliculties have heretofore been encountered in accurately maintaining the liquid level in the jacket when the liquid control apparatus is located remote from the water jacket. The liquid must flow by gravity from the reservoir to the water jacket. When the ice making apparatus is stopped, the liquid levels in the jacket and water reservoir can equalize. However, when the ice making apparatus is in operation, the liquid level in the jacket drops due to the flow impedance of the conduit, which connects the reservoir and jacket. In accordance with the present invention, the reservoir is formed on one side of the jacket 10 and has one side 86 of the reservoir in open communication with the water jacket. This arrangement not only assures free communication between the reservoir 80 and the liquid chamber 50, but also enables the use of a relatively smaller reservoir since the liquid chamber effectively forms a continuation of the reservoir. Moreover, with this arrangement the reservoir is removable as a unit with the water jacket for cleaning and servicing. If desired, a grid or screen (not shown) can be provided at the side of the reservoir 80 adjacent the liquid chamber 50 to prevent flake ice from entering the reservoir.

' A modified formof ice making apparatus is illustrated in FIGS. 5 and 6. As in the preceding embodiment, the ice making apparatus includes a jacket 110, an evaporator 111, an ice removing device 112 and a drive mechanism 113. The evaporator includes an inner shell 121 which is closed at one end by a wall 122 and which has the refrigerant supply and return conduits 118a, 11% and 119 extending into the other end thereof. The shell 121 is closed by a plug 123 which is sealed to the shell and to the inlet and return conduits. Enlarged portions are formed at opposite ends of the shell and define peripheral walls 125 and 126 spaced radially outwardly from the shell 121, and an outer sleeve 128 is affixed to the walls 125 and 126 and extends in spaced relation to the shell 121 to define a refrigerant chamber therebetween. In this embodiment, the refrigerant chamber is divided into segregated flow passages by a plurality of helical tubes 131a131d. As shown, refrigerant is supplied from one of the conduits 118a to the tube 131a adjacent one end it is forced upwardly.

of the evaporator and the refrigerant flows in helical fashion through the tube 131a to the other end of the evaporator. The tubes 131a and 131b are interconnected at 137 and the refrigerant flows back through tube 131!) to an outlet opening 139 which communicates with the accumulator chamber 141. The other refrigerant supply tube 11% is connected to conduit 131d at 136 and the refrigerant flows in helical fashion to the other end of the evaporator. Conduits 131d and 1310 are interconnected at 138 so that the refrigerant flows back to the first mentioned end of the evaporator and out through an outlet 140. The refrigerant return line 119 extends into the accumulator chamber 141 and communicates therewith adjacent the top of the chamber at 142. Thus, refrigerant is passed along the freezing wall 128 from relatively opposite ends to provide substantially uniform cooling of the freezing wall. As will be seen, the ends 139 and 140 of the tubes 131a-131d are connected to the accumulator chamber 141 formed by the inner shell 121 and define an enclosed refrigerant expansion vessel therewith. This expansion vessel is connected at 135 and 136 to the refrigerant supply lines 118a and 118b and to the refrigerant return line 119 to form a closed refrigeration system with a compressor and the condenser of the type shown at 16 and 17 in FIG. 1. The sleeve 128 which forms the freezing wall is advantageously bonded to the be removed and replaced in the field if it becomes Worn 'or corroded during use, without opening the closed refrigeration system. The soft-solder 150 is illustrated in FIG. 6 but has been omitted from FIG. 5 to clarify the drawing.

The evaporator is also formed with a head 143 which is attached to the outer jacket 110 and sealed thereto as by a gasket 144. As in the preceding embodiment, the ice removing device 112 is also preferably in the form of an axially expansible and contractible helical member having a blunt ice engaging surface, and the ice removing device is secured to a drive member 152 at one end. 'As best shown in FIG. 5, the drive member 152 is connected to the drive shaft 174 of the drive mechanism 113.

' The liquid level control apparatus 114 also includes a pressure supply line 181, a valve 182, a reservoir 180 and a float mechanism 183 for operating the valve. As in .the preceding embodiment, the reservoir 180 is advantageously attached to the jacket and has one side 186 in open communication therewith to assure that the liquid level is accurately maintained in the water jacket.

The ice removing device operates to separate the ice from the freezing wall 128 and feed the same axially to a discharge opening 151 in the water jacket. In accordance with the present invention, provision is made for compacting the flake ice product and for delivering the compacted ice mass in discrete chunks or blocks. As shown in FIG. 5, a delivery chute 191 is mounted on the jacket and extends upwardly around the discharge opening 151. The discharge chute is of tapered configuration and tapers to a relatively smaller cross opening at its upper end 193, to progressively compact the ice as An arched deflector 194 is provided at the upper end of the chute to deflect the column of compacted ice laterally and to form the same into separate chunks or blocks.

It will thus be seen that in both embodiments refrigerant is passed along the freezing wall from relatively opposite ends through segregated side-by-side passages to effect substantially uniform cooling of the freezing wall throughout its length. This produces a more uniform ice layer on the freezing wall so that the force required to remove the ice layer from the different portions of the wall is substantially uniform. The formation of the freezing wall as a separate tubular sleeve enables the use of low cost tubular stock for the freezing wall and further achieves economies in plating the freezing wall since the tubes can be plated prior to cutting in sections for the evaporators to eliminate individual plating of the evaporator shells. Further, the use of a heat-shrink fit for attaching the freezing walls to the evaporator bodies provides firm radial support for the freezing wall and enables use of relatively thinner wall sections for improved heat conduction. In the embodiment shown in FIGS. 5 and 6, the freezing wall can be removed from the evaporator without opening the sealed refrigeration system to facilitate repair and replacement of corroded or worn shells even in the field.

I claim:

1. In an apparatus for freezing liquids including an evaporator having a freezing wall, a refrigerating apparatus having refrigerant supply and return lines, means for supplying liquid to be frozen to one side of said wall, and an ice removing device for removing frozen liquid from said one side of the wall; the improvement which comprises means defining at least two segregated refrigerant fiow passages extending along the other side of the freezing wall, a first means connecting said refrigerant supply line to one of said flow passages adjacent one end of the wall; a second means connecting said refrigerant supply line to the other of said flow passages adjacent the other end of the wall, and means communicating said refrigerant return line to each of said flow passages at a point therealong spaced from the respective inlet whereby to pass refrigerant from the supply line along the freezing Wall from relatively opposite ends thereof for substantially uniform cooling of the freezing wall in the zone intermediate the ends of the refrigerant flow passages.

2. In an apparatus for freezing liquids including an evaporator having .a freezing wall, a refrigerating apparatus having refrigerant supply and return lines, means for supplying liquid to be frozen to one side of said wall, and an ice removing device for removing frozen liquid from said one side of the Wall, the improvement which comprises means defining at least two segregated refrigerant flow passages extending in side-by-side relation and in helical fashion along the other side of the freezing wall, a first means connecting said refrigerant supply line to one of said flow passages adjacent one end of the wall, a second means connecting said refrigerant supply line to the other of said flow passages adjacent the other end of said wall, and means communicating the other ends of each of said flow passages to said refrigerant return line whereby to pass refrigerant in helical fashion along the wall from opposite ends for substantially uniform cooling of the wall in the zone intermediate the ends of the refrigerant fiow passages.

3. In an apparatus for freezing liquids including an evaporator having a freezing wall, a refrigerating apparatus having refrigerant supply and return lines, means for supplying liquid to be frozen to one side of said wall,

and an ice removing device for removing frozen liquid from said one side of the wall; the improvement which comprises means defining first and second generally helical flow passages at said other side of said freezing wall jacent the respective inlet, means connecting the inlets of the first and second flow passages to the refrigerant supply line, and means connecting the outlets of the first and second flow passages to said return line.

4. In an apparatus for freezing liquids including an evaporator having a freezing wall, a liquid jacket surrounding said wall in spaced relation thereto for maintaining a quantity of liquid around the outside of the freezing wall, means including a rotary ice removing device disposed between said jacket and said freezing wall for removing frozen liquid therefrom, and refrigerating apparatus including refrigerant supply and return lines for cooling said freezing Wall; the improvement Which comprises means disposed inside said freezing wall defining at least two segregrated refrigerant passages extending along the inside of the freezing wall, a first means connecting the refrigerant supply line to one of said fiow passages adjacent one end of said freezing Wall, a second means connecting said refrigerant supply line to the other of said flow passages adjacent the other end of said freezing wall, and means connecting said refrigerant return line with each of said flow passages at points spaced therealong from the respective inlet whereby to pass refrigerant from the supply line along the freezing wall from relatively opposite ends thereof.

5. In an apparatus for freezing liquids including an evaporator having a freezing wall, a liquid jacket surrounding said wall in spaced relation thereto for maintaining a quantity of liquid around the outside of the freezing Wall, means including a rotary ice removing device disposed between the jacket and the freezing wall for removing frozen liquid therefrom, and refrigerating apparatus including refrigerant supply and return lines for cooling said freezing wall; the improvement which comprises an inner shell disposed within said freezing wall in spaced relation thereto and defining an inner accumulator chamber, means extending between said inner shell and said wall defining at least two segregated refrigerant fiow passages extending in side-by-side relation and in helical fashion along the inner side of the freezing wall, a first means connecting said refrigerant supply line to one of said flow passages at a point adjacent one end of said freezing Wall, a second means connecting said refrigerant supply line to the other of said flow passages at a point adjacent the other end of said freezing wall, means com municating the other ends of said flow passages with said inner shell, said refrigerant return line communicating with said inner shell at a point spaced above the bot-tom thereof.

6. The combination of claim wherein said means defining said fiow passages comprises helical ribs projecting from the outer periphery of said inner shell, said freezing 'wall closely surrounding said ribs.

7. The combination of claim 5 wherein said means defining said fiow passages comprises helical tubes surrounding said inner shell, said freezing Wall closely surrounding said tubes, and a soft-solder filling the space between the tubes and the freezing wall, said solder being of a type having a melting point below the boiling point of water to enable removal of the freezing wall from the tubes of the evaporator by the application of hot water to the freezing wall.

8. In combination with a refrigerating apparatus including a compressor; condenser; refrigerant expansion control; and refrigerant supply and return lines, an evaporator having a drum shaped outer shell and an inner evaporator means, said inner evaporator means defining an enclosed refrigerant expansion vessel connected to said supply and return lines to form a closed refrigeration system with said refrigerating apparatus, said evaporator means having a generally drum shaped external configuration, said outer shell being separate from said inner evaporator means and extending around said inner evaporator means and having an opening at least at one end to enable axial insertion and removal of the outer shell from around the inner evaporator means, the outer shell being removable from said inner evaporator means without opening the enclosed refrigerant expansion vessel defined by said inner evaporator means, a soft solder bonding the outer shell to the inner evaporator means in heat transmitting relation therewith, said soft solder being of a type having a melting point below the boiling point of Water to enable softening of the solder for removal of the outer shell from the inner evaporator means by the application of hot water to the outer shell, a water jacket surrounding the outer shell for maintaining a quantity of water in contact there- With, and means including a rotary ice removing device disposed between the outer shell and jacket for removing frozen liquid from the outer shell.

9. The combination of claim 8 wherein said enclosed refrigerant expansion vessel includes an inner shell defining an enclosed accumulator chamber and at least one tube in the form of a coil disposed around the inner shell, the tube having one end communicating with the accumulator chamber and the other end communicating with the refrigerant inlet line, the refrigerant return line communicating with the accumulator chamber.

10. In combination with a refrigeration apparatus including a compressor; a condenser; refrigerant expansion control; and refrigerant supply and return lines, an evaporator having a drum shaped outer shell and an inner evaporator means, said inner evaporator means including a tube formed in a coil and defining an enclosed refrigerant expansion vessel connected to said supply and return lines to form a closed refrigeration system With said refrigerating apparatus, said coil having a generally drum shaped external configuration, said outer shell being separate from said inner evaporator means and extending around said coil and having an opening at least at one end to enable axial insertion and removal of the outer shell from around the coil, said outer shell being removable from said inner evaporator means without opening the enclosed refrigerant expansion vessel defined by said inner evaporator means, a soft solder bonding the outer shell to the coil and filling the spaces between the coil and the outer shell to provide heatexchange therebetween, said soft-solder being of the type having a melting point below the boiling point of water to enable softening of the solder for removal of the outer shell from the coil by the application of hot water to the outer shell, a Water jacket surrounding the outer shell for maintaining a quantity of water in contact therewith, and means including a rotary ice removing device disposed between the outer shell and jacket for removing frozen liquid from the outer shell.

11. A liquid freezing apparatus comprising a liquid jacket, an evaporator assembly extending into said liquid jacket, a rotary ice removing device disposed between the jacket and evaporator assembly for removing frozen liquid from the evaporator assembly, said evaporator assembly including an inner body having an intermediate section and first and second end sections rigidly connected to said intermediate section adjacent opposite ends of the latter to form a rigid core-like structure,

said first and second end sections having cylindrical outer walls and said intermediate section having a cross-section smaller than said end sections, a sleeve open at both ends disposed around said inner body in spaced relation to said intermediate section and in sealed relation with said end sections to define an evaporator chamber between the sleeve and the intermediate section, partition means extending between said sleeve and said intermediate section to radially support the sleeve and for dividing said chamber into at least one refrigerant flow passage, and means for passing refrigerant through said refrigerant flow passage to cool said sleeve.

12. The combination of claim 11 wherein said partition means comprises ribs integral with said intermediate section.

13. The combination of claim 11 wherein said partition means comprises a spiral tube.

14. The combination of claim 11 wherein said sleeve is disposed in heat-shrink fit with said end sections and said partition means.

References Cited in the file of this patent UNITED STATES PATENTS Braswell Mar. 25, 1952 Ogden Dec. 23, 1952 

8. IN COMBINATION WITH A REFRIGERATING APPARATUS INCLUDING A COMPRESSOR; CONDENSER; REFRIGERANT EXPANSION CONTROL; AND REFRIGERANT SUPPLY AND RETURN LINES, AN EVAPORATOR HAVING A DRUM SHAPED OUTER SHELL AND AN INNER EVAPORATOR MEANS, SAID INNER EVAPORATOR MEANS DEFINING AN ENCLOSED REFRIGERANT EXPANSION VESSEL CONNECTED TO SAID SUPPLY AND RETURN LINES TO FORM A CLOSED REFRIGERATION SYSTEM WITH SAID REFRIGERATING APPARATUS, SAID EVAPORATOR MEANS HAVING A GENERALLY DRUM SHAPED EXTERNAL CONFIGURATION, SAID OUTER SHELL BEING SEPARATE FROM SAID INNER EVAPORATOR MEANS AND EXTENDING AROUND SAID INNER EVAPORATOR MEANS AND HAVING AN OPENING AT LEAST AT ONE END TO ENABLE AXIAL INSERTION AND REMOVAL OF THE OUTER SHELL FROM AROUND THE INNER EVAPORATOR MEANS, THE OUTER SHELL BEING REMOVABLE FROM SAID INNER EVAPORATOR MEANS WITHOUT OPENING THE ENCLOSED REFRIGERANT EXPANSION VESSEL DEFINED BY SAID INNER EVAPORATOR MEANS, A SOFT SOLDER BONDING THE OUTER SHELL TO THE INNER EVAPORATOR MEANS IN HEAT TRANSMITTING RELATION THEREWITH, SAID SOFT SOLDER BEING OF A TYPE HAVING A MELTING POINT BELOW THE BOILING POINT OF WATER TO ENABLE SOFTENING OF THE SOLDER FOR REMOVAL OF THE OUTER SHELL FROM THE INNER 